1. Field of the Invention
The present invention relates to a method of displaying a shape of a material and a shape of a product in a machining simulation, wherein the shape of the material, the shape of the product, and a shape of a tool are displayed as images on a display unit, wherein the displayed image of the tool is moved on the display unit on the basis of previously generated tool path data, wherein the image of the material and the image of the product which overlap the image of the tool are eliminated in order.
2. Description of the Prior Art
In an NC machine tool, a tool and a work piece are relatively moved and their movements are controlled on the basis of a previously generated machining program, while it is necessary that the machining program should be previously checked whether or not it has an error in case that a machining is performed for the first time on the basis of the machining program.
Usually, a machining simulation has been well known as an effective method for a pre-check. The machining simulation is executed by displaying a shape of a material, a shape of a product, and a shape of a tool on such as a display unit that is installed as an additional device of a numerical controller, and by moving the displayed image of the tool on the display unit on the basis of previously generated tool path data, also by eliminating the image of the material and the image of the product which overlap the image of the tool in order. Thus, a track of the tool can be identified, also a positional relationship between the tool and the material can be identified, whereby it is possible to previously check whether or not the machining program was correctly generated.
For displaying the shape of the material and (or) the shape of the product on the display unit, dimensions of all portions thereof such as an outer diameter, an inner diameter, and (or) a position of an end face have been usually inputted into a machining simulation apparatus for defining the shape of the material and the shape of the product for the purpose of displaying them on the display unit.
By the way, there are several kinds of materials used for a machining, for example, a material of a comparatively simple shape such as a cylindrical shape or a column shape, a molding material which has such a shape that a uniform machining allowance is added to the shape of the product through a forging and (or) a precision casting, and (or) a composite material which has a portion with the uniform machining allowance as well as a portion with a uniformly varying machining allowance. Further, there are some which include portions not to be machined in the molding material as well as in the composite material. In the molding material and the composite material, the portion with the uniform machining allowance can be defined in its shape such that the machining allowance is added to the shape of the product.
However, in the usual machining simulation, the shape of the material has been defined by inputting all dimensions of each part of the material as mentioned above, therefore it has taken a long time to input them in such a case that the shape of the material is very complicated, consequently a speedy simulation has not been enabled.
In case that the material include the portion not to be machined, the track of the tool doesn""t pass therethrough, therefore it is usually unnecessary to display the shape of the product and the shape of the material with reference to the portion not to be machined when checking the machining program, however, in the usual machining simulation, dimensions of the portion not to be machined have been also inputted for displaying the whole shape. In this point, the speedy simulation has not been enabled, either.
In view of the foregoing, it is an object of the invention to provide a method of displaying the shape of the material and the shape of the product which enables a speedy machining simulation.
In accordance with the invention for achieving the above object, in a machining simulation which displays a shape of a material, a shape of a product, and a shape of a tool on a display unit, and moves a displayed image of the tool on the display unit on the basis of previously generated tool path data, and eliminates an image of the material and an image of the product overlapping the image of the tool in order, the machining simulation is characterized in that the shape of the product in accordance with a portion to be machined is displayed as a line image wherein only an outline of the product is illustrated on the basis of dimension data of the product, on the other hand, the shape of the material in accordance with the portion to be machined is displayed as a plane image which illustrates an area in correspondence with the machining allowance on the basis of machining allowance data in case that the material includes the portion to be machined which is formed by adding a specified machining allowance to the outline of the product.
As described above, in case that the material includes the portion to be machined formed by adding the uniform machining allowance to the outline of the product, that is, the material is a molding material or a composite material, the portion with the uniform machining allowance can be defined in its shape such that the machining allowance is added to the shape of the product. Therefore, when displaying the shape of the material and the shape of the product on the display unit, dimension data of each portion of the material isn""t necessary to be inputted for defining the shape of the material, on the contrary, the shape of the material can be defined just by inputting only dimension data of the product and data of the machining allowance, as a result the shape of the material and the shape of the product can be displayed on the display unit only on the basis of those data.
In a method of display in accordance with the invention, in case that the material includes the portion to be machined which is formed by adding the specified machining allowance to the outline of the product, that is, the material is the molding material or the composite material, the shape of the product in accordance with the portion to be machined is displayed as the line image which illustrates only the outline of the product on the basis of dimension data of the product, while the shape of the material in accordance with the portion to be machined is displayed as the plane image which illustrates the area in correspondence with the machining allowance on the basis of data of the machining allowance through the input of only dimension data of the product and data of the machining allowance. Thus, a data input in relation to the shape of the material is simplified and a time taken for the data input is shortened, whereby a speedy machining simulation is enabled.
In addition, it is preferable that the plane image which illustrates the shape of the material is formed by outwardly off-setting the line image by the machining allowance for simplifying a displaying process, wherein the line image illustrates the shape of the product.
Further, it is also preferable that the shape of the product and the shape of the material in accordance with the portion not to be machined should not be displayed in case that the material includes the portion not to be machined for preventing unnecessary data input.
The line image showing the shape of the product may be displayed by a pixel group in correspondence with the outline of the product and by another pixel group which is inwardly arranged from the former pixel group at least by one pixel. In this case, the line image is illustrated with using a line of a thickness of two or more pixels.
As described above, in case that the material includes the portion to be machined which is formed by adding the specified machining allowance to the outline of the product, that is, the material is the molding material or the composite material, the shape of the product in accordance with the portion to be machined is displayed as the line image which illustrates only the outline of the product, on the other hand, the shape of the material is displayed as the plane image which illustrates the area in correspondence with the machining allowance. In this case, through an execution of the machining simulation, the image of the material and the image of the product which overlap the image of the tool are eliminated in order following after the movement of the image of the tool. Thus, whole the image of the material and the image of the product in accordance with the portion to be machined have been eliminated at a time when the machining simulation had been completed, whereby it cannot be possible to chase whether or not the tool had been moved correctly after the completion of the machining simulation.
However, above-mentioned problem can be removed by displaying the line image which illustrates the shape of the product with a line having a thickness of two or more pixels. That is, the line image is eliminated only by one pixel by the image of the tool which moves on the outline of the shape of the product, however, the remaining pixels are still displayed on the display unit as the line image illustrating the shape of the product, therefore it can be recognized whether or not the tool had been moved correctly even after the completion of the machining simulation. Thus, the problem as mentioned above which happens by simplifying the data input can be eliminated.